/* SDSLib, A C dynamic strings library
 *
 * Copyright (c) 2006-2012, Salvatore Sanfilippo <antirez at gmail dot com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of Redis nor the names of its contributors may be used
 *     to endorse or promote products derived from this software without
 *     specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include "sds.h"

sds sdsnewlen(const void *init, size_t initlen) {
  struct sdshdr *sh;

  if (init) {
    sh = malloc(sizeof(struct sdshdr)+initlen+1);
  } else {
    sh = calloc(sizeof(struct sdshdr)+initlen+1, sizeof(char));
  }
  if (sh == NULL) return NULL;
  sh->len = initlen;
  sh->free = 0;
  if (initlen && init)
    memcpy(sh->buf, init, initlen);
  sh->buf[initlen] = '\0';
  return (char*)sh->buf;
}

sds sdsempty(void) {
  return sdsnewlen("",0);
}

sds sdsnew(const char *init) {
  size_t initlen = (init == NULL) ? 0 : strlen(init);
  return sdsnewlen(init, initlen);
}

sds sdsdup(const sds s) {
  return sdsnewlen(s, sdslen(s));
}

void sdsfree(sds s) {
  if (s == NULL) return;
  free(s-sizeof(struct sdshdr));
}

void sdsupdatelen(sds s) {
  struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
  int reallen = strlen(s);
  sh->free += (sh->len-reallen);
  sh->len = reallen;
}

void sdsclear(sds s) {
  struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
  sh->free += sh->len;
  sh->len = 0;
  sh->buf[0] = '\0';
}

/* Enlarge the free space at the end of the sds string so that the caller
 * is sure that after calling this function can overwrite up to addlen
 * bytes after the end of the string, plus one more byte for nul term.
 *
 * Note: this does not change the *size* of the sds string as returned
 * by sdslen(), but only the free buffer space we have. */
sds sdsMakeRoomFor(sds s, size_t addlen) {
  struct sdshdr *sh, *newsh;
  size_t free = sdsavail(s);
  size_t len, newlen;

  if (free >= addlen) return s;
  len = sdslen(s);
  sh = (void*) (s-(sizeof(struct sdshdr)));
  newlen = (len+addlen);
  if (newlen < SDS_MAX_PREALLOC)
    newlen *= 2;
  else
    newlen += SDS_MAX_PREALLOC;
  newsh = realloc(sh, sizeof(struct sdshdr)+newlen+1);
  if (newsh == NULL) return NULL;

  newsh->free = newlen - len;
  return newsh->buf;
}

/* Reallocate the sds string so that it has no free space at the end. The
 * contained string remains not altered, but next concatenation operations
 * will require a reallocation. */
sds sdsRemoveFreeSpace(sds s) {
  struct sdshdr *sh;

  sh = (void*) (s-(sizeof(struct sdshdr)));
  sh = realloc(sh, sizeof(struct sdshdr)+sh->len+1);
  sh->free = 0;
  return sh->buf;
}

size_t sdsAllocSize(sds s) {
  struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));

  return sizeof(*sh)+sh->len+sh->free+1;
}

/* Increment the sds length and decrements the left free space at the
 * end of the string accordingly to 'incr'. Also set the null term
 * in the new end of the string.
 *
 * This function is used in order to fix the string length after the
 * user calls sdsMakeRoomFor(), writes something after the end of
 * the current string, and finally needs to set the new length.
 *
 * Note: it is possible to use a negative increment in order to
 * right-trim the string.
 *
 * Using sdsIncrLen() and sdsMakeRoomFor() it is possible to mount the
 * following schema to cat bytes coming from the kernel to the end of an
 * sds string new things without copying into an intermediate buffer:
 *
 * oldlen = sdslen(s);
 * s = sdsMakeRoomFor(s, BUFFER_SIZE);
 * nread = read(fd, s+oldlen, BUFFER_SIZE);
 * ... check for nread <= 0 and handle it ...
 * sdsIncrLen(s, nhread);
 */
void sdsIncrLen(sds s, int incr) {
  struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));

  assert(sh->free >= incr);
  sh->len += incr;
  sh->free -= incr;
  assert(sh->free >= 0);
  s[sh->len] = '\0';
}

/* Grow the sds to have the specified length. Bytes that were not part of
 * the original length of the sds will be set to zero. */
sds sdsgrowzero(sds s, size_t len) {
  struct sdshdr *sh = (void*)(s-(sizeof(struct sdshdr)));
  size_t totlen, curlen = sh->len;

  if (len <= curlen) return s;
  s = sdsMakeRoomFor(s,len-curlen);
  if (s == NULL) return NULL;

  /* Make sure added region doesn't contain garbage */
  sh = (void*)(s-(sizeof(struct sdshdr)));
  memset(s+curlen,0,(len-curlen+1)); /* also set trailing \0 byte */
  totlen = sh->len+sh->free;
  sh->len = len;
  sh->free = totlen-sh->len;
  return s;
}

sds sdscatlen(sds s, const void *t, size_t len) {
  struct sdshdr *sh;
  size_t curlen = sdslen(s);

  s = sdsMakeRoomFor(s,len);
  if (s == NULL) return NULL;
  sh = (void*) (s-(sizeof(struct sdshdr)));
  memcpy(s+curlen, t, len);
  sh->len = curlen+len;
  sh->free = sh->free-len;
  s[curlen+len] = '\0';
  return s;
}

sds sdscat(sds s, const char *t) {
  return sdscatlen(s, t, strlen(t));
}

sds sdscatsds(sds s, const sds t) {
  return sdscatlen(s, t, sdslen(t));
}

sds sdscpylen(sds s, const char *t, size_t len) {
  struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
  size_t totlen = sh->free+sh->len;

  if (totlen < len) {
    s = sdsMakeRoomFor(s,len-sh->len);
    if (s == NULL) return NULL;
    sh = (void*) (s-(sizeof(struct sdshdr)));
    totlen = sh->free+sh->len;
  }
  memcpy(s, t, len);
  s[len] = '\0';
  sh->len = len;
  sh->free = totlen-len;
  return s;
}

sds sdscpy(sds s, const char *t) {
  return sdscpylen(s, t, strlen(t));
}

sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
  va_list cpy;
  char *buf, *t;
  size_t buflen = 16;

  while(1) {
    buf = malloc(buflen);
    if (buf == NULL) return NULL;
    buf[buflen-2] = '\0';
    va_copy(cpy,ap);
    vsnprintf(buf, buflen, fmt, cpy);
    if (buf[buflen-2] != '\0') {
      free(buf);
      buflen *= 2;
      continue;
    }
    break;
  }
  t = sdscat(s, buf);
  free(buf);
  return t;
}

sds sdscatprintf(sds s, const char *fmt, ...) {
  va_list ap;
  char *t;
  va_start(ap, fmt);
  t = sdscatvprintf(s,fmt,ap);
  va_end(ap);
  return t;
}

sds sdstrim(sds s, const char *cset) {
  struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
  char *start, *end, *sp, *ep;
  size_t len;

  sp = start = s;
  ep = end = s+sdslen(s)-1;
  while(sp <= end && strchr(cset, *sp)) sp++;
  while(ep > start && strchr(cset, *ep)) ep--;
  len = (sp > ep) ? 0 : ((ep-sp)+1);
  if (sh->buf != sp) memmove(sh->buf, sp, len);
  sh->buf[len] = '\0';
  sh->free = sh->free+(sh->len-len);
  sh->len = len;
  return s;
}

sds sdsrange(sds s, int start, int end) {
  struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
  size_t newlen, len = sdslen(s);

  if (len == 0) return s;
  if (start < 0) {
    start = len+start;
    if (start < 0) start = 0;
  }
  if (end < 0) {
    end = len+end;
    if (end < 0) end = 0;
  }
  newlen = (start > end) ? 0 : (end-start)+1;
  if (newlen != 0) {
    if (start >= (signed)len) {
      newlen = 0;
    } else if (end >= (signed)len) {
      end = len-1;
      newlen = (start > end) ? 0 : (end-start)+1;
    }
  } else {
    start = 0;
  }
  if (start && newlen) memmove(sh->buf, sh->buf+start, newlen);
  sh->buf[newlen] = 0;
  sh->free = sh->free+(sh->len-newlen);
  sh->len = newlen;
  return s;
}

void sdstolower(sds s) {
  int len = sdslen(s), j;

  for (j = 0; j < len; j++) s[j] = tolower(s[j]);
}

void sdstoupper(sds s) {
  int len = sdslen(s), j;

  for (j = 0; j < len; j++) s[j] = toupper(s[j]);
}

int sdscmp(const sds s1, const sds s2) {
  size_t l1, l2, minlen;
  int cmp;

  l1 = sdslen(s1);
  l2 = sdslen(s2);
  minlen = (l1 < l2) ? l1 : l2;
  cmp = memcmp(s1,s2,minlen);
  if (cmp == 0) return l1-l2;
  return cmp;
}

/* Split 's' with separator in 'sep'. An array
 * of sds strings is returned. *count will be set
 * by reference to the number of tokens returned.
 *
 * On out of memory, zero length string, zero length
 * separator, NULL is returned.
 *
 * Note that 'sep' is able to split a string using
 * a multi-character separator. For example
 * sdssplit("foo_-_bar","_-_"); will return two
 * elements "foo" and "bar".
 *
 * This version of the function is binary-safe but
 * requires length arguments. sdssplit() is just the
 * same function but for zero-terminated strings.
 */
sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count) {
  int elements = 0, slots = 5, start = 0, j;
  sds *tokens;

  if (seplen < 1 || len < 0) return NULL;

  tokens = malloc(sizeof(sds)*slots);
  if (tokens == NULL) return NULL;

  if (len == 0) {
    *count = 0;
    return tokens;
  }
  for (j = 0; j < (len-(seplen-1)); j++) {
    /* make sure there is room for the next element and the final one */
    if (slots < elements+2) {
      sds *newtokens;

      slots *= 2;
      newtokens = realloc(tokens,sizeof(sds)*slots);
      if (newtokens == NULL) goto cleanup;
      tokens = newtokens;
    }
    /* search the separator */
    if ((seplen == 1 && *(s+j) == sep[0]) || (memcmp(s+j,sep,seplen) == 0)) {
      tokens[elements] = sdsnewlen(s+start,j-start);
      if (tokens[elements] == NULL) goto cleanup;
      elements++;
      start = j+seplen;
      j = j+seplen-1; /* skip the separator */
    }
  }
  /* Add the final element. We are sure there is room in the tokens array. */
  tokens[elements] = sdsnewlen(s+start,len-start);
  if (tokens[elements] == NULL) goto cleanup;
  elements++;
  *count = elements;
  return tokens;

cleanup:
  {
    int i;
    for (i = 0; i < elements; i++) sdsfree(tokens[i]);
    free(tokens);
    *count = 0;
    return NULL;
  }
}

void sdsfreesplitres(sds *tokens, int count) {
  if (!tokens) return;
  while(count--)
    sdsfree(tokens[count]);
  free(tokens);
}

sds sdsfromlonglong(long long value) {
  char buf[32], *p;
  unsigned long long v;

  v = (value < 0) ? -value : value;
  p = buf+31; /* point to the last character */
  do {
    *p-- = '0'+(v%10);
    v /= 10;
  } while(v);
  if (value < 0) *p-- = '-';
  p++;
  return sdsnewlen(p,32-(p-buf));
}

sds sdscatrepr(sds s, const char *p, size_t len) {
  s = sdscatlen(s,"\"",1);
  while(len--) {
    switch(*p) {
      case '\\':
      case '"':
        s = sdscatprintf(s,"\\%c",*p);
        break;
      case '\n': s = sdscatlen(s,"\\n",2); break;
      case '\r': s = sdscatlen(s,"\\r",2); break;
      case '\t': s = sdscatlen(s,"\\t",2); break;
      case '\a': s = sdscatlen(s,"\\a",2); break;
      case '\b': s = sdscatlen(s,"\\b",2); break;
      default:
        if (isprint(*p))
          s = sdscatprintf(s,"%c",*p);
        else
          s = sdscatprintf(s,"\\x%02x",(unsigned char)*p);
        break;
    }
    p++;
  }
  return sdscatlen(s,"\"",1);
}

/* Helper function for sdssplitargs() that returns non zero if 'c'
 * is a valid hex digit. */
int is_hex_digit(char c) {
  return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') ||
      (c >= 'A' && c <= 'F');
}

/* Helper function for sdssplitargs() that converts an hex digit into an
 * integer from 0 to 15 */
int hex_digit_to_int(char c) {
  switch(c) {
    case '0': return 0;
    case '1': return 1;
    case '2': return 2;
    case '3': return 3;
    case '4': return 4;
    case '5': return 5;
    case '6': return 6;
    case '7': return 7;
    case '8': return 8;
    case '9': return 9;
    case 'a': case 'A': return 10;
    case 'b': case 'B': return 11;
    case 'c': case 'C': return 12;
    case 'd': case 'D': return 13;
    case 'e': case 'E': return 14;
    case 'f': case 'F': return 15;
    default: return 0;
  }
}

/* Split a line into arguments, where every argument can be in the
 * following programming-language REPL-alike form:
 *
 * foo bar "newline are supported\n" and "\xff\x00otherstuff"
 *
 * The number of arguments is stored into *argc, and an array
 * of sds is returned.
 *
 * The caller should free the resulting array of sds strings with
 * sdsfreesplitres().
 *
 * Note that sdscatrepr() is able to convert back a string into
 * a quoted string in the same format sdssplitargs() is able to parse.
 *
 * The function returns the allocated tokens on success, even when the
 * input string is empty, or NULL if the input contains unbalanced
 * quotes or closed quotes followed by non space characters
 * as in: "foo"bar or "foo'
 */
sds *sdssplitargs(const char *line, int *argc) {
  const char *p = line;
  char *current = NULL;
  char **vector = NULL;

  *argc = 0;
  while(1) {
    /* skip blanks */
    while(*p && isspace(*p)) p++;
    if (*p) {
      /* get a token */
      int inq=0;  /* set to 1 if we are in "quotes" */
      int insq=0; /* set to 1 if we are in 'single quotes' */
      int done=0;

      if (current == NULL) current = sdsempty();
      while(!done) {
        if (inq) {
          if (*p == '\\' && *(p+1) == 'x' &&
              is_hex_digit(*(p+2)) &&
              is_hex_digit(*(p+3)))
          {
            unsigned char byte;

            byte = (hex_digit_to_int(*(p+2))*16)+
                hex_digit_to_int(*(p+3));
            current = sdscatlen(current,(char*)&byte,1);
            p += 3;
          } else if (*p == '\\' && *(p+1)) {
            char c;

            p++;
            switch(*p) {
              case 'n': c = '\n'; break;
              case 'r': c = '\r'; break;
              case 't': c = '\t'; break;
              case 'b': c = '\b'; break;
              case 'a': c = '\a'; break;
              default: c = *p; break;
            }
            current = sdscatlen(current,&c,1);
          } else if (*p == '"') {
            /* closing quote must be followed by a space or
             * nothing at all. */
            if (*(p+1) && !isspace(*(p+1))) goto err;
            done=1;
          } else if (!*p) {
            /* unterminated quotes */
            goto err;
          } else {
            current = sdscatlen(current,p,1);
          }
        } else if (insq) {
          if (*p == '\\' && *(p+1) == '\'') {
            p++;
            current = sdscatlen(current,"'",1);
          } else if (*p == '\'') {
            /* closing quote must be followed by a space or
             * nothing at all. */
            if (*(p+1) && !isspace(*(p+1))) goto err;
            done=1;
          } else if (!*p) {
            /* unterminated quotes */
            goto err;
          } else {
            current = sdscatlen(current,p,1);
          }
        } else {
          switch(*p) {
            case ' ':
            case '\n':
            case '\r':
            case '\t':
            case '\0':
              done=1;
              break;
            case '"':
              inq=1;
              break;
            case '\'':
              insq=1;
              break;
            default:
              current = sdscatlen(current,p,1);
              break;
          }
        }
        if (*p) p++;
      }
      /* add the token to the vector */
      vector = realloc(vector,((*argc)+1)*sizeof(char*));
      vector[*argc] = current;
      (*argc)++;
      current = NULL;
    } else {
      /* Even on empty input string return something not NULL. */
      if (vector == NULL) vector = malloc(sizeof(void*));
      return vector;
    }
  }

err:
  while((*argc)--)
    sdsfree(vector[*argc]);
  free(vector);
  if (current) sdsfree(current);
  *argc = 0;
  return NULL;
}

/* Modify the string substituting all the occurrences of the set of
 * characters specified in the 'from' string to the corresponding character
 * in the 'to' array.
 *
 * For instance: sdsmapchars(mystring, "ho", "01", 2)
 * will have the effect of turning the string "hello" into "0ell1".
 *
 * The function returns the sds string pointer, that is always the same
 * as the input pointer since no resize is needed. */
sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen) {
  size_t j, i, l = sdslen(s);

  for (j = 0; j < l; j++) {
    for (i = 0; i < setlen; i++) {
      if (s[j] == from[i]) {
        s[j] = to[i];
        break;
      }
    }
  }
  return s;
}

#ifdef SDS_TEST_MAIN
#include <stdio.h>
#include "testhelp.h"

int main(void) {
  {
    struct sdshdr *sh;
    sds x = sdsnew("foo"), y;

    test_cond("Create a string and obtain the length",
              sdslen(x) == 3 && memcmp(x,"foo\0",4) == 0)

        sdsfree(x);
    x = sdsnewlen("foo",2);
    test_cond("Create a string with specified length",
              sdslen(x) == 2 && memcmp(x,"fo\0",3) == 0)

        x = sdscat(x,"bar");
    test_cond("Strings concatenation",
              sdslen(x) == 5 && memcmp(x,"fobar\0",6) == 0);

    x = sdscpy(x,"a");
    test_cond("sdscpy() against an originally longer string",
              sdslen(x) == 1 && memcmp(x,"a\0",2) == 0)

        x = sdscpy(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk");
    test_cond("sdscpy() against an originally shorter string",
              sdslen(x) == 33 &&
              memcmp(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk\0",33) == 0)

        sdsfree(x);
    x = sdscatprintf(sdsempty(),"%d",123);
    test_cond("sdscatprintf() seems working in the base case",
              sdslen(x) == 3 && memcmp(x,"123\0",4) ==0)

        sdsfree(x);
    x = sdstrim(sdsnew("xxciaoyyy"),"xy");
    test_cond("sdstrim() correctly trims characters",
              sdslen(x) == 4 && memcmp(x,"ciao\0",5) == 0)

        y = sdsrange(sdsdup(x),1,1);
    test_cond("sdsrange(...,1,1)",
              sdslen(y) == 1 && memcmp(y,"i\0",2) == 0)

        sdsfree(y);
    y = sdsrange(sdsdup(x),1,-1);
    test_cond("sdsrange(...,1,-1)",
              sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0)

        sdsfree(y);
    y = sdsrange(sdsdup(x),-2,-1);
    test_cond("sdsrange(...,-2,-1)",
              sdslen(y) == 2 && memcmp(y,"ao\0",3) == 0)

        sdsfree(y);
    y = sdsrange(sdsdup(x),2,1);
    test_cond("sdsrange(...,2,1)",
              sdslen(y) == 0 && memcmp(y,"\0",1) == 0)

        sdsfree(y);
    y = sdsrange(sdsdup(x),1,100);
    test_cond("sdsrange(...,1,100)",
              sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0)

        sdsfree(y);
    y = sdsrange(sdsdup(x),100,100);
    test_cond("sdsrange(...,100,100)",
              sdslen(y) == 0 && memcmp(y,"\0",1) == 0)

        sdsfree(y);
    sdsfree(x);
    x = sdsnew("foo");
    y = sdsnew("foa");
    test_cond("sdscmp(foo,foa)", sdscmp(x,y) > 0)

        sdsfree(y);
    sdsfree(x);
    x = sdsnew("bar");
    y = sdsnew("bar");
    test_cond("sdscmp(bar,bar)", sdscmp(x,y) == 0)

        sdsfree(y);
    sdsfree(x);
    x = sdsnew("aar");
    y = sdsnew("bar");
    test_cond("sdscmp(bar,bar)", sdscmp(x,y) < 0)

    {
      int oldfree;

      sdsfree(x);
      x = sdsnew("0");
      sh = (void*) (x-(sizeof(struct sdshdr)));
      test_cond("sdsnew() free/len buffers", sh->len == 1 && sh->free == 0);
      x = sdsMakeRoomFor(x,1);
      sh = (void*) (x-(sizeof(struct sdshdr)));
      test_cond("sdsMakeRoomFor()", sh->len == 1 && sh->free > 0);
      oldfree = sh->free;
      x[1] = '1';
      sdsIncrLen(x,1);
      test_cond("sdsIncrLen() -- content", x[0] == '0' && x[1] == '1');
      test_cond("sdsIncrLen() -- len", sh->len == 2);
      test_cond("sdsIncrLen() -- free", sh->free == oldfree-1);
    }
  }
  test_report()
      return 0;
}
#endif
